As the crystals are all scattered around, it's finally time for good boys and girls to head back down to the ground.

Which is when Haibara makes her grand reappearance. Was she waiting for this moment? Or is it simply good timing?

"Ishigami-san!" She's trying to wave him down, and approaching as she does. Once she's a little closer, "Give me a ride back down. You're still planning on using your second potion, right?"

If he gives her a lift, then she can hold onto her second potion. Mission accomplished.